Fig. 1

Scanning electron micrographs (SEM) of uterine epithelial tissues from patients on LH + 7. A Absence of pinopodes. Secretory cells are covered by microvilli (white arrow). B Developing pinopodes. the small semi-spherical projection in the apical membrane is covered by short and sparse microvilli (white arrow). C Fully developed pinopodes. Microvilli have disappeared from the projections which appear to be fully maximally distended (white arrow). D Regressing pinopodes. The projections have a wrinkled surface (white arrow); small microvilli tips reappeared on the membranes. E Comparison of the proportion of the various coverage of pinopodes between the two groups. F SEM of pinopodes were graded semi-quantitatively. Control: receptive control (n = 10); RIF: recurrent implantation failure (n = 20)